Extensive and steady research has found novel values from omega 3 fatty acids, including EPA (eicosa pentaenoic acid) and DHA (docosa hexaenoic acid), both found uniquely in fish oil, and they are now recognized as being highly valuable to the health of the body. A workshop on omega 3 and omega 6 fatty acids was held in Italy, 1988, under the supervision of Nutritional Science Section, International Biotechnology Institute of North Atlantic Treaty Organization (NATO), in which 120 scientists from 15 countries reached a consensus that omega 3 fatty acid should be supplied appropriately to the body and has a function of lowering cholesterol levels in blood in addition to being useful for anti-blood coagulation and anti-inflammation and rheumatoid arthritis treatment.
As mentioned, omega 3 fatty acid, which is contained in fish oil, is regarded as an essential fatty acid necessary to keep humans healthy. To be processed to a food or foodstuff, however, fish oil should typically be refined and deodorized on account of its characteristic offensive odor and ready liability to deterioration. In this regard, high techniques using expensive special apparatuses or high cost fermenting methods are used, so that an increase occurs in the production cost of refined fish oil, standing in the way of providing omega 3 fatty acid to many people at low costs.
The applicant has suggested an economically favorable method in removing fish odor and the utilization method of the deodorized fish oil as animal feed in Korean Patient Publication No. 93-779 entitled "A deodorization processing method of fish oil using mono sodium glutamate (MSG) by-product," which was matured into Korean Pat. No. 062232 on May 25, 1993, and Korean Patent No. 123840 entitled "Animal feed manufacturing method based on fish oil," yielded on Sep. 19, 1997, respectively.
In Korean Pat. Publication No. 93-779, it is described that an MSG by-product is mixed to fish oil together with water in order to remove phospholipid which is a main cause of fish smell contained in the fish oil. Then, the mixed resultant is heated to transpose oil-soluble phospholipids of the fish oil into water-soluble ones by means of water soluble protein in the MSG. The transposed water-soluble phospholipid is separated from the fish oil by a separation method, thereby floating its fat to an upper portion of the pure fish oil. If the floated fat is removed, the phospholipid contained in the fish oil is effectively eradicated.
The fish oil from which the phospholipid is removed is pre-heated at the atmosphere of vacuum. The odor of the fish oil is removed by water evaporation at the atmosphere of vacuum, to eliminate unsaturated fatty acid. Then, the unsaturated fatty acid is cooled to complete a separation process. Thereafter, since a peroxide value (POV) is not more than 10 milimol per kilogram even though about three weeks elapse, the bad smell is not generated.
As described above, since the MSG by-product is added to the fish oil to remove the phospholipid, and then the pre-heating, the deodorization and the cooling processes at the atmosphere of vacuum lower the degree of degeneration, the deodorization of the smell of the fish oil can be accomplished at an extremely low cost and through a simple process. Also, the low POV can be maintained for a long time, the fish oil can be kept for a long time.
Disclosed in Korean Pat. No. 123840 (corresponding to U.S. Pat. No. 5,693,358, yielded on Dec. 2, 1997) is a method for powdering the fish oil obtained from the above method. The method comprises heating a mixture of fish oil with water and an MSG by-product with stirring, reacting the mixture at an elevated temperature in the presence of urea as a catalyst with stirring and fermenting the mixture with steams, separately eradicating water and phospholipids from the fermented fish oil, and powdering the fish oil by adding quicklime, cooling, saponification, salting-out and rolling. After being mixed with animal feed, the powdered quicklime-added fish oil is provided for poultry.
When the resulting animal feed is provided to egg-laying hens, there can be obtained eggs whose yolks contain EPA and DHA. Chickens or pigs which are bred with the feed provide chicken meat or pork transposed by omega 3 fatty acids, such as EPA and DHA. Feeding of the feed to milk cows results in the production of the milk containing omega 3 fatty acid such as DHA at relatively low costs.
Since DHA is known to play an important role in improving retina reflex and intelligence development, the provision of such omega 3 fatty acids is helpful in ensuring children to have sound bodies and improved intelligence.